ATP hydrolysis is required for DEAD-box protein recycling but not for duplex unwinding
ATP hydrolysis is required for DEAD-box protein recycling but not for duplex unwinding
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DOI：
10.1073/pnas.0811115106
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发表时间：
2008-12-23
影响因子：
11.1
通讯作者：
Jankowsky, Eckhard
中科院分区：
文献类型：
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作者：
Liu, Fei;Putnam, Andrea;Jankowsky, Eckhard
DEAD-box 蛋白是最大的解旋酶家族，催化 RNA-蛋白复合物的 ATP 依赖性重塑和 RNA 双链体的解旋。由于 DEAD-box 蛋白以 RNA 依赖性方式水解 ATP，因此通常认为 ATP 水解提供的能量会驱动能量上不利的双链体解旋。在这里，我们展示了在不可水解的 ATP 类似物 ADP-氟化铍存在的情况下，几种 DEAD-box 蛋白对稳定双链体的有效解旋。另一种 ATP 类似物 ADP-氟化铝不会促进解旋。研究结果表明，ATP 水解产生的能量对于链分离来说是可有可无的。然而，ATP 结合似乎是必要的。研究发现，ATP 水解是酶从 RNA 中快速释放和多次底物周转以及酶回收所必需的。
DEAD-box proteins, the largest helicase family, catalyze ATP-dependent remodeling of RNA-protein complexes and the unwinding of RNA duplexes. Because DEAD-box proteins hydrolyze ATP in an RNA-dependent fashion, the energy provided by ATP hydrolysis is commonly assumed to drive the energetically unfavorable duplex unwinding. Here, we show efficient unwinding of stable duplexes by several DEAD-box proteins in the presence of the nonhydrolyzable ATP analog ADP-beryllium fluoride. Another ATP analog, ADP-aluminum fluoride, does not promote unwinding. The findings show that the energy from ATP hydrolysis is dispensable for strand separation. ATP binding, however, appears necessary. ATP hydrolysis is found to be required for fast enzyme release from the RNA and multiple substrate turnovers and thus for enzyme recycling.